A telescoping shaft assembly capable of transmitting a torque is often used in a driveline system as a torque-transmitting mechanism. The telescopic shaft assembly typically includes a tubular outer shaft member and an inner shaft member. The inner shaft member is at least partially disposed within the outer shaft member and moveable relative thereto along a longitudinal axis. The telescopic shaft assembly typically uses rolling elements between the outer and inner shaft members to reduce friction therebetween.
The rolling elements of the telescopic shaft assembly typically include linear bearings and often include steel rollers or steel balls. The rolling elements are configured to roll between the outer and inner shaft members during telescoping movement of the telescopic shaft assembly while continuing to transmit torque.
A telescopic shaft configured to connect two constant-velocity joints is known, wherein redundant rolling-element grooves have been added to an outer shaft member of the telescopic shaft to minimize distortion during heat-treatment. However, only one-half or one-third of the grooves is functional (i.e., used for transmitting torque). This configuration restricts compactness of packaging for a given torque capacity once a minimum web (i.e., section between adjacent functional grooves) has been reached, limiting a chordal distance between the grooves. In a configuration in which the outer shaft member has two or three times a number of grooves than has an inner shaft member, the web in the inner shaft member always is larger than that in the outer shaft member.